Radio frequency performance testing method and apparatus of wireless device, and tester

ABSTRACT

A method for testing radio frequency performance of a wireless device is provided. Power level reporting information of a device under test is obtained. A propagation matrix is obtained based on the power level reporting information. An inverse matrix is obtained based on the propagation matrix to form a virtual cable between an output port of an instrument and a receiver port of the device under test. A throughput test signal is transmitted through the virtual cable to perform a performance test on the device under test and to obtain a test result of the radio frequency performance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2019/113244, filed on Oct. 25, 2019, which claims priority toChinese Patent Application No. 201811620599.3, filed on Dec. 28, 2018,the entire contents of which are incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to a field of performance testingtechnologies of wireless device, and more particularly, to a method anda device for testing radio frequency performance of wireless device anda related tester.

BACKGROUND

In the related art, usually, a conduction method is adopted to test theradio frequency performance of a wireless device. For example, asillustrated in FIG. 1 , antenna performance of the wireless device maybe tested through the conduction method, and a conduction cable isconnected to a receiver to test performance of the receiver. Therefore,obtained results may be combined as the radio frequency performance ofthe entire device.

SUMMARY

Embodiments of the present disclosure provide a method for testing radiofrequency performance of a wireless device. In one embodiment, themethod includes: obtaining power level reporting information of a deviceunder test; obtaining a propagation matrix based on the power levelreporting information, and obtaining an inverse matrix loaded based onthe propagation matrix to form a virtual cable between an output port ofan instrument and a receiver port of the device under test; andtransmitting a throughput test signal via the virtual cable to perform aperformance test on the device under test and generate a test result ofthe radio frequency performance.

Embodiments of the present disclosure provide a tester. The tester mayobtain the propagation matrix based on the power level reportinginformation, and form the virtual cable between the output port of theinstrument and the receiver port of the device under test, to performthe performance test on the device under test and generate the testresult of the radio frequency performance.

Embodiments of the present disclosure provide a non-transitory computerreadable storage medium, having instruction stored thereon. When theinstructions are executed by a processor, the processor is caused toexecute a method for testing radio frequency performance of a wirelessdevice described above.

Additional aspects and advantages of the present disclosure will begiven in part in the following description, part of which will becomeapparent from the following description, or be learned through practiceof the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or additional aspects and advantages of embodiments of thepresent disclosure will become apparent and more readily appreciatedfrom the following descriptions made with reference to the drawings, inwhich:

FIG. 1 is a schematic diagram illustrating principles of testing radiofrequency performance of a wireless device using a conduction method inthe related art.

FIG. 2 is a schematic diagram illustrating principles of MIMO OTA testin the related art.

FIG. 3 is a schematic diagram illustrating principles of connecting aradio frequency matrix module to test antennas in the related art.

FIG. 4 is a schematic diagram illustrating that test ports and receiverports are connected by N virtual cables in the related art.

FIG. 5 is a schematic diagram illustrating principles of a radiatedtwo-stage method for a MIMO test in the related art.

FIG. 6 is a flowchart illustrating a method for testing radio frequencyperformance of a wireless device according to embodiments of the presentdisclosure.

FIG. 7 is a schematic diagram of a signal outputted by test antenna 1according to embodiments of the present disclosure.

FIG. 8 is a schematic diagram of a signal outputted by test antenna 2according to embodiments of the present disclosure.

FIG. 9 is a schematic diagram of signals outputted by test antenna 1 andtest antenna 2 according to embodiments of the present disclosure.

FIG. 10 is a schematic diagram illustrating signal propagationsrepresented by a formula according to embodiments of the presentdisclosure.

FIG. 11 is a schematic diagram of testing a device under test placed inan anechoic chamber according to embodiments of the present disclosure.

FIG. 12 is a schematic diagram illustrating a device for testing radiofrequency performance of a wireless device according to embodiments ofthe present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in detail andexamples of embodiments are illustrated in the drawings. The same orsimilar elements and the elements having the same or similar functionsare denoted by like reference numerals throughout the descriptions.Embodiments described herein with reference to drawings are explanatory,serve to explain the present disclosure, and are not construed to limitembodiments of the present disclosure. An existing conduction cable iscoupled to a conduction feed point of a device under test, the radiofrequency matching of the device under test may be changed, whichfurther changes the performance of the antenna and the receiver.

Further, the current may be coupled to the conduction cable, which makesthe cable part of the device under test.

Further, in a normal operation mode, interference noise of the deviceunder test can be coupled to the receiver through the antenna, causingan interference to the receiver. However, after a conduction connectoris connected, the noise cannot be coupled to the receiver, and thus atest result does not reflect an actual result.

Further, in a 5G wireless terminal, due to limited size and cost of thedevice under test, there is generally no radio frequency connector left,which makes the conduction test impossible.

Therefore, the conduction test in the related art not only has errorsthat lead to inaccurate testing, but also has limitations.

The present disclosure provides a method for testing radio frequencyperformance of a wireless device, which can realize virtual cables basedon power level reporting information.

With the method for testing radio frequency performance of a wirelessdevice according to embodiments of the present disclosure, thepropagation matrix may be obtained based on the power level reportinginformation, and the virtual cable is formed between the output port ofthe instrument and the receiver port of the device under test, toperform the performance test on the device under test and generate thetest result of the radio frequency performance. This method may obtainthe solution of the virtual cable based on the power level reportinginformation, thereby improving the accuracy, efficiency, andapplicability of the test.

Before describing the method and device for testing radio frequencyperformance of a wireless device according to embodiments of the presentdisclosure, how this disclosure is proposed based on knowledge anddiscovery of inventors on following problems will be described briefly.

Currently, an OTA (over the air) test is mainly used to evaluate theradio frequency performance of the wireless device in an unconnectedstate (no radio frequency cable is connected to a device under test), toobtain an evaluation on the true radio frequency performance of thewireless device.

In detail, the OTA test has become a standard international test methodfor evaluating the radio frequency performance of the wireless device.For example, passing OTA certification test to ensure that theperformance of wireless electronic products meets the standard withoutcausing interference to the electromagnetic environment is the key tomarket access. The OTA test may include several standards, e.g., twotest standards for a single-input single-output (SISO) system, i.e.,total radiated power (TRP) and total isotropic sensitivity (TIS), and atest standard for a multiple-input multiple-output (MIMO) system, i.e.,throughput. Domestic development organization of standards of the OTAtest is China Communications Standards Association (CCSA), andinternational development organization of standards of the OTA test is3rd Generation Partnership Project (3GPP).

In the MIMO OTA test, “virtual cable” technology is adopted widely. Indetail, as illustrated in FIG. 2 , a device under test with multipleantennas is placed in a shielded chamber. The number M of test antennasis equal to the number N of antennas of the device under test.Electromagnetic waves are transmitted through the N test antennas andreach N feed points of receiving antennas forming a stable propagationmatrix which is represented as propagation matrix P. The propagationmatrix P is an N×N matrix.

A radio frequency matrix module is connected to the test antennas. Asillustrated in FIG. 3 , the value of the radio frequency matrix V is setto be equal to an inverse of the propagation matrix P, that is, P=V⁻¹. Nsignals (T₁, T₂, . . . , T_(N)) at the test ports and N received signals(R₁, R₂, . . . , R_(N)) at the receiver ports satisfy a followingrelation:(R ₁ ,R ₂ , . . . ,R _(N))^(T) =P*V*(T ₁ ,T ₂ , . . . ,T _(N))^(T)=(T ₁,T ₂ , . . . ,T _(N))^(T),where, ( )^(T) represents transpose of a matrix.

The above formula shows that, with the above setting, the signal fromthe test port may be directly fed into the receiver port, similar toconnecting via conduction cables, except a difference that the deviceunder test is in an independent working state without any connection ofintrusive cables. Therefore, the test results are the real workingperformance. This operating manner is also called “virtual cable”technology. As illustrated in FIG. 4 , N virtual cables re connected tothe test ports and the receiver ports.

The virtual cable technology may be applied to various tests. One is aradiated two-stage method as an international standard for MIMO testing.For example, a fast, accurate, and economical radiated two-stage methodfor MIMO OTA test is disclosed in the related art. The radiatedtwo-stage method is to calculate, through a computer, a signal thatshould reach each receiver (that is, the throughput test signal thatshould reach each receiver), and directly transmit the test signal tothe corresponding receiver through the virtual cable, thus enablesimultaneous transmission of multiple signals for throughput test.

In detail, the radiated two-stage method for the MIMO test isillustrated in FIG. 5 . The test process mainly includes the followingsteps.

In the first step, multiple antenna patterns of multiple antennas of aMIMO wireless terminal are obtained.

In the second step, the multiple antenna patterns of the multipleantennas of the wireless terminal are combined with a pre-determinedMIMO propagation channel model to obtain a complete MIMO propagationchannel by simulation, and to generate a throughput test signal.

In the third step, a propagation matrix is determined for a device undertest placed in a shielded chamber, an inverse matrix is obtained basedon the propagation matrix, and the inverse matrix is loaded to form avirtual cable between an output port of the channel simulator and areceiver port of the device under test.

In the fourth step, the throughput test signal is transmitted throughthe virtual cable to test the wireless terminal.

However, in many special cases, it is difficult to implement the virtualcable.

For example, as illustrated in FIG. 2 , a spatial propagation matrix Pis:

${P = \begin{bmatrix}{p_{11}e^{{j\chi}_{11}}} & {p_{12}e^{{j\chi}_{12}}} & \text{…} & {p_{1N}e^{{j\chi}_{1N}}} \\{p_{21}e^{{j\chi}_{21}}} & {p_{22}e^{{j\chi}_{22}}} & \text{…} & {p_{2N}e^{j\chi_{2N}}} \\\vdots & \vdots & \ddots & \vdots \\{p_{N1}e^{j\chi_{N\; 1}}} & {p_{N2}e^{j\chi_{N2}}} & \text{…} & {p_{NN}e^{j\chi_{NN}}}\end{bmatrix}},$

where, p_(xy) represents a change in amplitude of a signal sent from ay^(th) test antenna to a x^(th) antenna, and e^(jχ) ^(xy) represents achange in phase of the signal sent from the y^(th) test antenna to thex^(th) antenna. In other words, p_(xy)e^(jχ) ^(xy) is the S parameterfrom the y^(th) test antenna to the x^(th) antenna.

Information of the matrix P should be known to solve the inverse matrixof the spatial propagation matrix P. However, in OTA test, the deviceunder test is not connected to any conduction cable, which means thatthere is no reference basis used to calculate an absolute phase betweenthe test antenna and the receiver port of the device under test.Therefore, χ_(xy) of the propagation matrix P is unknown. Therefore,theoretically, the inverse matrix of the matrix P cannot be solved.

The related art, such as “Inverse Matrix Solving Method for SolvingElectromagnetic Wave Propagation Matrix Based on Antenna Patterns using2×2 Inverse Matrix” discloses an inverse matrix solving method based onthe information reported by the device under test using the 2×2 radiatedtwo-stage method. However, this method is not applicable for a case ofN>2. In addition, the related art, such as “Signal Generation Method andDevice based on MIMO Wireless Terminal Test” discloses an inverse matrixsolving method based on the information reported by the device undertest using the M×N radiated two-stage method. In detail, in this method,amplitude information of the matrix P and phase difference of otherelements in each column of the matrix P with respect to a first elementof that column may be obtained from the information reported by thedevice under test. For example, in a first column of the matrix P:

$\quad{\begin{bmatrix}{p_{11}e^{j\chi_{11}}} \\{p_{21}e^{j\chi_{21}}} \\\vdots \\{p_{N1}e^{j\chi_{N\; 1}}}\end{bmatrix},}$a value of χ_(nt) relative to χ₁₁ may be obtained based on informationreported by the device under test (in this case, the value of χ₁₁ isunknown). The inverse matrix may be solved depending on this reportedphase information. This method is suitable for some devices under test.However, the method may have the following defectives.

1. For the device under test that cannot report phase information, it isunable to obtain the phase difference, and thus the calculation cannotbe performed. For example, some array antennas or multi-antenna routersdo not have an ability to test and report phase information.

2. For the device under test with inaccurate phase reporting, thismethod is limited, especially when N is relatively large, and thus theaccuracy of the phase reporting affects the accuracy of virtual cablesolution.

When faced with the above problems, the present disclosure provides amethod and a device, for testing radio frequency performance of awireless device and a related tester.

The method and the device for testing radio frequency performance of awireless device and the related tester according to embodiments of thepresent disclosure will be described below with reference to thedrawings. In details, the method for testing radio frequency performanceof a wireless device according to embodiments of the present disclosureis described with reference to the drawings firstly.

FIG. 6 is a flowchart illustrating a method for testing radio frequencyperformance of a wireless device according to embodiments of the presentdisclosure.

As illustrated in FIG. 6 , the method for testing radio frequencyperformance of a wireless device may include the following.

At block S101, power level reporting information of a device under testis obtained.

In an embodiment of the present disclosure, the power level reportinginformation is obtained, by reporting, by the device under test throughthe antenna, power of the signal received by each receiver, or bystoring locally and exporting the power received.

It may be understood that, in embodiments of the present disclosure, itonly requires that the device under test provides the power levelreporting information. In current communication standard, the deviceunder test generally has a power level reporting function, such as GSM,WiFi, LTE, and ZigBee. However, there is no standard to require thewireless terminal having a phase reporting function. and the testaccuracy based on the power level reporting is higher than that based onthe phase reporting. Therefore, embodiments of the present disclosuremay accurately and universally solve and implement the virtual cables.

At block S102, the propagation matrix is obtained based on the powerlevel reporting information, and an inverse matrix to be loaded isobtained based on the propagation matrix, to form a virtual cablebetween an output port of an instrument and a receiver port of thedevice under test.

In an embodiment of the present disclosure, obtaining the propagationmatrix based on the power level reporting information includes:obtaining an amplitude value based on the power level reportinginformation; and obtaining a phase difference of elements in thepropagation matrix based on the amplitude value to obtain thepropagation matrix.

In an embodiment of the present disclosure, the test is performed basedon a formula:

${\begin{bmatrix}R_{1} \\R_{2} \\\vdots \\R_{N}\end{bmatrix} = {{E^{*}\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = {{\begin{bmatrix}e^{j\chi_{11}} & 0 & \text{…} & 0 \\0 & e^{j{(\chi_{21})}} & \text{…} & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \text{…} & e^{j{(\chi_{N\; 1})}}\end{bmatrix}*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = \begin{bmatrix}{{T_{1}}^{*}e^{{j\chi}_{11}}} \\{{T_{2}}^{*}e^{{j\chi}_{21}}} \\\vdots \\{{T_{N}}^{*}e^{{j\chi}_{N\; 1}}}\end{bmatrix}}}},$where, N represents the number of antennas of the device under test, Trepresents an excitation signal at each test port, R represents thereceived signal at each receiver port, e^(j(χ) ^(n1) ⁾ represents thephase information, and E is obtained from the propagation matrix.

In detail, a MIMO device under test with N antennas is placed in ashielded chamber (or an anechoic chamber having a shielding effect).There are more than N test antennas in the shielded chamber, asillustrated in FIG. 3 , and the N test antennas are connected to an N×Nradio frequency matrix module V. Excite each test port with a unitexcitation signal (amplitude and phase equal to each other). The deviceunder test has the power level reporting function. That is, the deviceunder test may report the power level of the signal received by eachreceiver to the test instrument through the antenna, or the powerreceived may be stored locally and exported.

For example, the inverse matrix is:

$V = {\begin{bmatrix}{v_{11}e^{{j\lambda}_{11}}} & {v_{12}e^{{j\lambda}_{12}}} & \text{…} & {v_{1N}e^{{j\lambda}_{1N}}} \\{v_{21}e^{{j\lambda}_{21}}} & {v_{22}e^{{j\lambda}_{22}}} & \text{…} & {v_{2N}e^{{j\lambda}_{2N}}} \\\vdots & \vdots & \ddots & \vdots \\{v_{N\; 1}e^{j\lambda_{N\; 1}}} & {v_{N2}e^{j\lambda_{N2}}} & \text{…} & {v_{NN}e^{j\lambda_{NN}}}\end{bmatrix}.}$

The propagation matrix P is unknown, and the propagation matrix P may beobtained as follow.

At block 1, the test port keeps the unit excitation signal (T₁, T₂, . .. , T_(N))=(1, 1, . . . , 1).

At block 2, the inverse matrix is written as:

${V = \begin{bmatrix}1 & 0 & \text{…} & 0 \\0 & 0 & \text{…} & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \text{…} & 0\end{bmatrix}},$meaning that only the test antenna 1 transmits a signal, as illustratedin FIG. 7 . The power levels (real number, converted into amplitudevalues) from the N receivers are obtained. That is, the amplitudeinformation of a first column of the matrix P is:

$\begin{bmatrix}p_{11} \\p_{21} \\\vdots \\p_{N1}\end{bmatrix}.$

At block 3, the inverse matrix is written as:

${V = \begin{bmatrix}0 & 0 & \text{…} & 0 \\0 & 1 & \text{…} & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \text{…} & 0\end{bmatrix}},$meaning that only the test antenna 2 transmits a signal, as illustratedin FIG. 8 . The power levels (real numbers, converted into amplitudevalues) from the N receivers are obtained. That is, the amplitudeinformation of a second column of the matrix P is:

$\begin{bmatrix}p_{12} \\p_{22} \\\vdots \\p_{N2}\end{bmatrix}.$

At block 4, the value of each remaining element on the diagonal of thematrix V is replaced with 1 in sequence, while other ones are replacedwith 0, all the amplitude information of the entire matrix P may beobtained as:

$\begin{bmatrix}p_{11} & p_{12} & \text{…} & p_{1N} \\p_{21} & p_{22} & \text{…} & p_{2N} \\\vdots & \vdots & \ddots & \vdots \\p_{N1} & p_{N2} & \text{…} & p_{NN}\end{bmatrix}.$

At block 5, a part of phase information is solved by a power synthesisalgorithm, including the following.

a. In the inverse matrix V, v₁₁e^(jλ) ¹¹ ′=1 and v₂₂ e^(jλ) ²² =1, andothers are 0, i.e.,

${V = \begin{bmatrix}1 & 0 & \text{…} & 0 \\0 & 1 & \text{…} & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \text{…} & 0\end{bmatrix}},$meaning that only the test antenna 1 and the test antenna 2 transmitsignals, as illustrated in FIG. 9 . The power levels (real numbers,converted into amplitude values) from the N receivers are obtained,which is:

$\begin{bmatrix}Q_{1} \\Q_{2} \\\vdots \\Q_{N}\end{bmatrix},$in this case, the power of each receiver is a synthesis of those signalson two paths. For example, for the n^(th) receiver, the amplitude of thereceived signal is:Q _(n)=√{square root over (p _(n1) ² +p _(n2) ²−2*p _(n1) *p_(n2)*cos(π−(χ_(n1)−χ_(n2))))}.

Since p_(n1), p_(n2) and Q_(n) are obtained in the above blocks, thesethree may be plugged into the above formula to obtain a value ofχ_(n1)−χ_(n2). Similarly, based on

$\begin{bmatrix}p_{11} \\p_{21} \\\vdots \\p_{N1}\end{bmatrix},{\begin{bmatrix}p_{12} \\p_{22} \\\vdots \\p_{N2}\end{bmatrix}\mspace{14mu}{{and}\mspace{14mu}\begin{bmatrix}Q_{1} \\Q_{2} \\\vdots \\Q_{N}\end{bmatrix}}},$the value of

$\quad\begin{bmatrix}{\chi_{11} - \chi_{12}} \\{\chi_{21} - \chi_{22}} \\\vdots \\{\chi_{N1} - \chi_{N2}}\end{bmatrix}$may be obtained. That is, for each row of the matrix P, the phasedifference of the elements on the second column relative to theelements, on the same row, on the first column may be calculated.

In addition, the value of v₂₂e^(jλ) ²² may be set to different values,and the received power level may be obtained to achieve more accuratesolution of

$\begin{bmatrix}{\chi_{11} - \chi_{12}} \\{\chi_{21} - \chi_{22}} \\\vdots \\{\chi_{N1} - \chi_{N2}}\end{bmatrix}.$

For example, the amplitudes of v₁₁e^(jλ) ¹¹ and v₂₂e^(jλ) ²² may begiven, and the phase difference of the elements on the second columnrelative to the elements on the first column may be calculated for eachrow through a rotation vector method.

b. Similarly, in the inverse matrix V, v₁₁e^(jλ) ¹¹ =1, v₃₃e^(jλ) ³³ =1,and others are 0. The power levels (real numbers, converted intoamplitude values) from the N receivers are obtained to solve the valueof

$\begin{bmatrix}{\chi_{11} - \chi_{13}} \\{\chi_{21} - \chi_{23}} \\\vdots \\{\chi_{N1} - \chi_{N\; 3}}\end{bmatrix}.$

That is, for each row of the matrix P, the phase difference of theelements on the third column relative to the elements, on the same row,on the first column can be calculated.

c. Similarly, for each row of the matrix P, the phase difference of theelements on the N^(th) column relative to the elements, on the same row,on the first column can be calculated. Therefore, the matrix P may be:

${P = \begin{bmatrix}{p_{11}e^{j\;\chi_{11}}} & {p_{12}e^{j{({\partial_{12}{+ \chi_{11}}})}}} & \ldots & {p_{1N}e^{j{({\partial_{1N}{+ \chi_{11}}})}}} \\{p_{21}e^{j\chi_{21}}} & {p_{22}e^{j{({\partial_{22}{+ \chi_{21}}})}}} & \ldots & {p_{2N}e^{j{({\partial_{2N}{+ \chi_{21}}})}}} \\\vdots & \vdots & \ddots & \vdots \\{p_{N1}e^{j\chi_{N\; 1}}} & {p_{N2}e^{j{({\partial_{N2}{+ \chi_{N\; 1}}})}}} & \ldots & {p_{NN}e^{j{({\partial_{NN}{+ \chi_{N\; 1}}})}}}\end{bmatrix}},$where, ∂_(xy) is a difference obtained by subtracting the change in thephase of the signal sent from the first test antenna to the x^(th)antenna from the change in the phase of the signal sent from the y^(th)test antenna to the x^(th) antenna, which may be obtained at the block5, where

$\quad\begin{bmatrix}\chi_{11} \\\chi_{21} \\\vdots \\\chi_{N1}\end{bmatrix}$is the change in the phase sent from the first test antenna to allreceiving antennas and is unknown.

From the above, the solution of the matrix P is completed. The inversematrix of P is solved as follows.

The matrix P may be expressed as:

$P = {\begin{bmatrix}{p_{11}e^{j\;\chi_{11}}} & {p_{12}e^{j{({\partial_{12}{+ \chi_{11}}})}}} & \ldots & {p_{1N}e^{j{({\partial_{1N}{+ \chi_{11}}})}}} \\{p_{21}e^{j\chi_{21}}} & {p_{22}e^{j{({\partial_{22}{+ \chi_{21}}})}}} & \ldots & {p_{2N}e^{j{({\partial_{2N}{+ \chi_{21}}})}}} \\\vdots & \vdots & \ddots & \vdots \\{p_{N1}e^{j\chi_{N\; 1}}} & {p_{N2}e^{j{({\partial_{N2}{+ \chi_{N\; 1}}})}}} & \ldots & {p_{NN}e^{j{({\partial_{NN}{+ \chi_{N\; 1}}})}}}\end{bmatrix} = {\begin{bmatrix}e^{j\;\chi_{11}} & 0 & \ldots & 0 \\0 & e^{j(\;\chi_{11})} & \ldots & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j(\;\chi_{N\; 1})}\end{bmatrix}\begin{bmatrix}p_{11} & {p_{12}e^{j{(\partial_{12})}}} & \ldots & {p_{1N}e^{j{(\partial_{1N})}}} \\p_{21} & {p_{22}e^{j{(\partial_{22})}}} & \ldots & {p_{2N}e^{j{(\partial_{2N})}}} \\\vdots & \vdots & \ddots & \vdots \\p_{N\; 1} & {p_{N\; 2}e^{j{(\partial_{N\; 2})}}} & \ldots & {p_{NN}e^{j{(\partial_{NN})}}}\end{bmatrix}}^{,}}$where,

${E = \begin{bmatrix}e^{j\chi_{II}} & 0 & \ldots & 0 \\0 & e^{j{(\chi_{21})}} & \ldots & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j{(\chi_{N\; 1})}}\end{bmatrix}},{and}$ $P_{B} = {\begin{bmatrix}p_{11} & {p_{12}e^{j{(\partial_{12})}}} & \ldots & {p_{1N}e^{j{(\partial_{1N})}}} \\p_{21} & {p_{22}e^{j{(\partial_{22})}}} & \ldots & {p_{2N}e^{j{(\partial_{2N})}}} \\\vdots & \vdots & \ddots & \vdots \\p_{N\; 1} & {p_{N2}e^{j{(\partial_{N2})}}} & \ldots & {p_{NN}e^{j{(\partial_{NN})}}}\end{bmatrix}.}$

The matrix E is unknown, and the matrix P_(B) is completely known(obtained through the above blocks).

The inverse matrix of the matrix P_(B) may be obtained as:

$P_{B}^{- 1} = {\begin{bmatrix}p_{11} & {p_{12}e^{j{(\partial_{12})}}} & \ldots & {p_{1N}e^{j{(\partial_{1N})}}} \\p_{21} & {p_{22}e^{j{(\partial_{22})}}} & \ldots & {p_{2N}e^{j{(\partial_{2N})}}} \\\vdots & \vdots & \ddots & \vdots \\p_{N\; 1} & {p_{N2}e^{j{(\partial_{N2})}}} & \ldots & {p_{NN}e^{j{(\partial_{NN})}}}\end{bmatrix}^{- 1}.}$

The matrix P_(B) ⁻¹ may be imported into the inverse matrix module, thatis, V=P_(B) ⁻¹.

The relation between the test signals (T₁, T₂, . . . , T_(N)) outputfrom the test ports and the signals (R₁, R₂, . . . , R_(N)) arriving atthe receiver ports is:

$\begin{bmatrix}R_{1} \\R_{2} \\\vdots \\R_{N}\end{bmatrix} = {{P*V*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = {P*P_{B}^{- 1}*{\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}.}}}$

Bring P=E*P_(B) to the above formula to obtain:

$\begin{bmatrix}R_{1} \\R_{2} \\\vdots \\R_{N}\end{bmatrix} = {{E*P_{B}*P_{B}^{- 1}*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = {{E*P_{B}*P_{B}^{- 1}*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = {E*{\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}.}}}}$

Bring the matrix E to the above formula to obtain:

$\begin{bmatrix}R_{1} \\R_{2} \\\vdots \\R_{N}\end{bmatrix} = {{E*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = {{\begin{bmatrix}e^{j\;\chi_{11}} & 0 & \ldots & 0 \\0 & e^{j(\;\chi_{21})} & \ldots & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j(\;\chi_{N\; 1})}\end{bmatrix}*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = {\begin{bmatrix}{T_{1}*e^{j\;\chi_{11}}} \\{T_{2}*e^{j\;\chi_{21}}} \\\vdots \\{T_{N}*e^{j\;\chi_{N\; 1}}}\end{bmatrix}.}}}$

The above formula shows that the received signal of the n^(th) receiveris completely from the n^(th) test port. Although the signal issuperimposed with an unknown phase information, this isolated one-to-onesignal transmission method is the virtual cable transmission technology.As illustrated in FIG. 10 , the signals are transmitted from the testports to the receivers in a one-to-one manner, as indicated by theformula.

At block S103, a throughput test signal is transmitted through thevirtual cable to perform a performance test on the device under test, togenerate a test result of the radio frequency performance.

In embodiments of the present disclosure, the solution of the virtualcable is realized when only the power level reporting of the deviceunder test is required, without depending on the phase information.Devices under test of various standards may be used in the methodaccording to embodiments of the present disclosure and the methodaccording to embodiments of the present disclosure may be used in theradiated two-stage method. The method is accurate, requires less stepsof solution and is fast.

In addition, in embodiments of the present disclosure, the methodfurther includes: obtaining multiple antenna patterns of multipleantennas of the device under test; and combining the antenna patternswith a pre-determined MIMO propagation channel model to obtain a MIMOpropagation channel by simulation and to generate a throughput testsignal.

For example, the method according to embodiments of the presentdisclosure may be used in the radiated two-stage method, which isdescribed in detail below.

In detail, the device under test is placed in an anechoic chamber, asillustrated in FIG. 11 , the method may include the following.

At block 1, multiple antenna patterns of multiple antennas of a MIMOwireless terminal are obtained.

At block 2, the multiple antenna patterns of the multiple antennas ofthe wireless terminal are combined with a pre-determined MIMOpropagation channel model to obtain a complete MIMO propagation channelby simulation and to generate a throughput test signal.

At block 3, a position of the device under test is fixed, and based onthe method according to the present disclosure, the propagation matrixin the anechoic chamber is determined based on the power level reportinginformation of the device under test, thus the inverse matrix to beloaded is determined, the inverse matrix is imported to form a virtualcable between the output port of the instrument and the receiver port ofthe device under test.

At block 4, the throughput test signal is transmitted through thevirtual cable to test the wireless terminal.

With the method for testing radio frequency performance of a wirelessdevice according to embodiments of the present disclosure, thepropagation matrix may be obtained based on the power level reportinginformation, and the virtual cable is formed between the output port ofthe instrument and the receiver port of the device under test, toperform the performance test on the device under test and generate thetest result of the radio frequency performance, without depending on thephase information. By obtaining the solution of the virtual cable basedon the power level reporting information, devices under test of variousstandards may be used in the method according to the present disclosureand the method according to the present disclosure may be used in theradiated two-stage method. The method is accurate, requires less stepsof solution and is fast. In addition, this method may improve accuracy,efficiency, and applicability of the test.

A device for testing radio frequency performance of a wireless deviceaccording to embodiments of the present disclosure is described withreference to the drawings.

FIG. 12 is a schematic diagram illustrating a device for testing radiofrequency performance of a wireless device according to embodiments ofthe present disclosure.

As illustrated in FIG. 12 , the device 10 for testing radio frequencyperformance of a wireless device include a collecting module 100, afirst obtaining module 200 and a testing module 300.

The collecting module 100 is configured to obtain power level reportinginformation of a device under test. The first obtaining module 200 isconfigured to obtain a propagation matrix based on the power levelreporting information and obtain an inverse matrix to be loaded based onthe propagation matrix to form a virtual cable between an output port ofan instrument and a receiver port of the device under test. The testingmodule 300 is configured to transmit a throughput test signal throughthe virtual cable to perform a performance test on the device under testand generate a test result of the radio frequency performance. Thedevice 10 may achieve the solution of the virtual cable based on thepower level reporting information, thereby improving accuracy,efficiency, and applicability of the test.

In embodiments of the present disclosure, the device 10 according toembodiments of the present disclosure further includes a secondobtaining module and a generating module.

The second obtaining module is configured to obtain multiple antennapatterns of multiple antennas of the device under test. The generatingmodule is configured to combine the multiple antenna patterns with apre-determined MIMO propagation channel model to obtain a MIMOpropagation channel by simulation and to generate a throughput testsignal.

In an embodiment of the present disclosure, the power level reportinginformation is obtained by reporting, by the device under test via theantenna, power of a signal received by each receiver, or by storinglocally and exporting the power received.

In an embodiment of the present disclosure, the first obtaining module200 includes an obtaining unit and a computing unit.

The obtaining unit is configured to obtain an amplitude value based onthe power level reporting information. The computing module isconfigured to obtain a phase difference of elements in the propagationmatrix based on the amplitude value to obtain the propagation matrix.

It should be noted that, the foregoing explanation of the embodiment ofthe method for testing radio frequency performance of a wireless deviceis also applicable for the device for testing radio frequencyperformance of a wireless device in embodiments, and details are notdescribed herein again.

With the device for testing radio frequency performance of a wirelessdevice according to embodiments of the present disclosure, thepropagation matrix may be obtained based on the power level reportinginformation, and the virtual cable may be formed between the output portof the instrument and the receiver port of the device under test, toperform the performance test on the device under test and generate thetest result of the radio frequency performance, without depending on thephase information. By obtaining the solution of the virtual cable basedon the power level reporting information, devices under test of variousstandards may be used and this device may be used in the radiatedtwo-stage method. The device is accurate, requires less steps ofsolution and is fast. In addition, the device may improve accuracy,efficiency, and applicability of the test.

Embodiments of the present disclosure further provide a tester. Thetester includes the above-mentioned device for testing radio frequencyperformance of a wireless device. The tester may obtain the propagationmatrix based on the power level reporting information, and form thevirtual cable between an output port of an instrument and a receiverport of the device under test, to perform a performance test on thedevice under test and generate a test result of the radio frequencyperformance, without depending on the phase information. By obtainingthe solution of the virtual cable based on the power level reportinginformation, devices under test of various standards may be used andthis tester may be used in the radiated two-stage method. This tester isaccurate, requires less steps of the solution and is fast. In addition,this tester may improve accuracy, efficiency, and applicability of thetest.

In addition, terms such as “first” and “second” are used herein forpurposes of description and are not intended to indicate or implyrelative importance or significance. Thus, the feature defined with“first” and “second” may comprise one or more this feature. In thedescription of the present disclosure, “a plurality of” means at leasttwo, for example, two or three, unless specified otherwise.

Reference throughout this specification to “an embodiment,” “someembodiments,” “an example,” “a specific example,” or “some examples,”means that a particular feature, structure, material, or characteristicdescribed in connection with the embodiment or example is included in atleast one embodiment or example of the present disclosure. Theappearances of the above phrases in various places throughout thisspecification are not necessarily referring to the same embodiment orexample of the present disclosure. Furthermore, the particular features,structures, materials, or characteristics may be combined in anysuitable manner in one or more embodiments or examples. In addition,different embodiments or examples and features of different embodimentsor examples described in the specification may be combined by thoseskilled in the art without mutual contradiction.

Although embodiments of present disclosure have been shown and describedabove, it should be understood that above embodiments are justexplanatory, and cannot be construed to limit the present disclosure,for those skilled in the art, changes, alternatives, and modificationscan be made to the embodiments without departing from spirit, principlesand scope of the present disclosure.

What is claimed is:
 1. A method for testing radio frequency performanceof a wireless device, comprising: obtaining power level reportinginformation of a device under test; obtaining a propagation matrix basedon the power level reporting information, and obtaining an inversematrix to be loaded based on the propagation matrix to form a virtualcable between an output port of an instrument and a receiver port of thedevice under test; and transmitting a throughput test signal through thevirtual cable to perform a performance test on the device under test andobtain a test result of the radio frequency performance, whereinobtaining the propagation matrix based on the power level reportinginformation comprises: obtaining an amplitude value based on the powerlevel reporting information; and obtaining a phase difference ofelements in the propagation matrix based on the amplitude value toobtain the propagation matrix, wherein the method further comprises:transmitting a first signal through a first test antenna to eachreceiver of the device under test, obtaining power level reportinginformation of each receiver, and converting the power level reportinginformation into a first amplitude value of a received first signalreceived by each receiver, wherein the first amplitude value of thereceived first signal corresponds to the first test antenna;transmitting a second signal through a second test antenna to eachreceiver, obtaining power level reporting information of each receiver,and converting the power level reporting information into a secondamplitude value of a received second signal received by each receiver,wherein the second amplitude value of the received second signalcorresponds to the second test antenna; repeating the transmitting asignal, the obtaining the power level reporting information, and theconverting the power level reporting information until the amplitudevalue of a received signal received by each receiver and correspondingto each test antenna is obtained; transmitting the first signal throughthe first test antenna and transmitting the second signal through thesecond test antenna to each receiver simultaneously, obtaining powerlevel reporting information of each receiver of the device under test,determining an amplitude value of a synthesized signal received by eachreceiver, and obtaining a phase difference between a received firstsignal received by each receiver and a received second signal receivedby each receiver based on the first amplitude value, the secondamplitude value and the amplitude value of the synthesized signal; andrepeating transmitting signals by every two test antennas, obtaining thepower level reporting information, determining the amplitude value ofthe synthesized signal, and obtaining the phase difference until thephase difference between received signals received by each receiver andcorresponding to every two test antennas is obtained, so as to obtainthe propagation matrix, wherein obtaining the inverse matrix to beloaded based on the propagation matrix comprises: expressing thepropagation matrix based on a following equation: $\begin{matrix}{P = \begin{bmatrix}{p_{11}e^{j\chi_{11}}} & {p_{12}e^{j({\partial_{12}{+ \chi_{11}}})}} & \ldots & {p_{1N}e^{j({\partial_{1N}{+ \chi_{11}}})}} \\{p_{21}e^{j\chi_{21}}} & {p_{22}e^{j({\partial_{22}{+ \chi_{21}}})}} & \ldots & {p_{2N}e^{j({\partial_{2N}{+ \chi_{21}}})}} \\ \vdots & \vdots & \ddots & \vdots \\{p_{N1}e^{j\chi_{N1}}} & {p_{N2}e^{j({\partial_{N2}{+ \chi_{N1}}})}} & \ldots & {p_{NN}e^{j({\partial_{NN}{+ \chi_{N1}}})}}\end{bmatrix}} \\{= {\begin{bmatrix}e^{j\chi_{11}} & 0 & \ldots & 0 \\0 & e^{j(\chi_{21})} & \ldots & 0 \\ \vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j(\chi_{N1})}\end{bmatrix}\begin{bmatrix}p_{11} & {p_{12}e^{j(\partial_{12})}} & \ldots & {p_{1N}e^{j(\partial_{1N})}} \\p_{21} & {p_{22}e^{j(\partial_{22})}} & \ldots & {p_{2N}e^{j(\partial_{2N})}} \\ \vdots & \vdots & \ddots & \vdots \\p_{N1} & {p_{N2}e^{j(\partial_{N2})}} & \ldots & {p_{NN}e^{j(\partial_{NN})}}\end{bmatrix}}} \\{E = {\begin{bmatrix}e^{j\chi_{11}} & 0 & \ldots & 0 \\0 & e^{j(\chi_{21})} & \ldots & 0 \\ \vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j(\chi_{N1})}\end{bmatrix}{and}}} \\{P_{B} = \begin{bmatrix}p_{11} & {p_{12}e^{j(\partial_{12})}} & \ldots & {p_{1N}e^{j(\partial_{1N})}} \\p_{21} & {p_{22}e^{j(\partial_{22})}} & \ldots & {p_{2N}e^{j(\partial_{2N})}} \\ \vdots & \vdots & \ddots & \vdots \\p_{N1} & {p_{N2}e^{j(\partial_{N2})}} & \ldots & {p_{NN}e^{j(\partial_{NN})}}\end{bmatrix}}\end{matrix}$ where N represents the number of test antennas and thenumber of receivers of the device under test, P is the propagationmatrix, p_(xy) represents a change in amplitude of a signal sent from ay^(th) test antenna to an x^(th) receiver, a value range for x and y is1 to N, e^(j(χ) ^(n1) ⁾ is phase information associated with a change inphase of the signal sent from the first test antenna to an n^(th)receiver and is unknown, ∂_(xy) is a phase difference obtained bysubtracting the change in the phase of the signal sent from the firsttest antenna to an x^(th) receiver from the change in the phase of thesignal sent from a y^(th) test antenna to the x^(th) receiver, E is amatrix of e^(j(χ) ^(n1) ⁾ obtained from the propagation matrix and isunknown, P_(B) is a matrix of p_(xy) and ∂_(xy) obtained from thepropagation matrix; and obtaining the inverse matrix based on the matrixP_(B).
 2. The method according to claim 1, further comprising: obtainingmultiple antenna patterns of multiple antennas of the device under test;and combining the multiple antenna patterns with a pre-determined MIMOpropagation channel model to obtain a MIMO propagation channel bysimulation and to generate a throughput test signal.
 3. The methodaccording to claim 1, wherein the power level reporting information isobtained by reporting, by the device under test through an antenna,power of a signal received by each receiver, or by storing locally andexporting power received.
 4. The method according to claim 1, wherein atest is performed based on a formula: ${\begin{bmatrix}R_{1} \\R_{2} \\\vdots \\R_{N}\end{bmatrix} = {{E*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = {{\begin{bmatrix}e^{j\;\chi_{11}} & 0 & \ldots & 0 \\0 & e^{j(\;\chi_{21})} & \ldots & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j(\;\chi_{N\; 1})}\end{bmatrix}*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = \begin{bmatrix}{T_{1}*e^{j\;\chi_{11}}} \\{T_{2}*e^{j\;\chi_{21}}} \\\vdots \\{T_{N}*e^{j\;\chi_{N\; 1}}}\end{bmatrix}}}},$ where, N represents the number of antennas of thedevice under test, T represents an excitation signal at each test port,R represents a received signal at each receiver port, e^(j(χ) ^(n1) ⁾represents phase information, and E is obtained from the propagationmatrix.
 5. A tester, configured to: obtain power level reportinginformation of a device under test; obtain a propagation matrix based onthe power level reporting information, and obtain an inverse matrix tobe loaded based on the propagation matrix to form a virtual cablebetween an output port of an instrument and a receiver port of thedevice under test; and transmit a throughput test signal through thevirtual cable to perform a performance test on the device under test andobtain a test result of radio frequency performance, wherein the testeris further configured to: obtain an amplitude value based on the powerlevel reporting information; and obtain a phase difference of elementsin the propagation matrix based on the amplitude value to obtain thepropagation matrix, the tester is further configured to: transmit afirst signal through a first test antenna to each receiver of the deviceunder test, obtain power level reporting information of each receiver,and convert the power level reporting information into a first amplitudevalue of a received first signal received by each receiver, wherein thefirst amplitude value of the received first signal corresponds to thefirst test antenna; transmit a second signal through a second testantenna to each receiver, obtain power level reporting information ofeach receiver, and convert the power level reporting information into asecond amplitude value of a received second signal received by eachreceiver, wherein the second amplitude value of the received secondsignal corresponds to the second test antenna; repeat the transmitting asignal, the obtaining the power level reporting information, and theconverting the power level reporting information until the amplitudevalue of a received signal received by each receiver and correspondingto each test antenna is obtained; transmit the first signal through thefirst test antenna and transmit the second signal through the secondtest antenna to each receiver simultaneously, obtain power levelreporting information of each receiver of the device under test,determine an amplitude value of a synthesized signal received by eachreceiver, and obtain a phase difference between a received first signalreceived by each receiver and a received second signal received by eachreceiver based on the first amplitude value, the second amplitude valueand the amplitude value of the synthesized signal; and repeattransmitting signals by every two test antennas, obtaining the powerlevel reporting information, determining the amplitude value of thesynthesized signal, and obtaining the phase difference until the phasedifference between received signals received by each receiver andcorresponding to every two test antennas is obtained, so as to obtainthe propagation matrix, wherein obtaining the inverse matrix to beloaded based on the propagation matrix comprises: expressing thepropagation matrix based on a following equation: $\begin{matrix}{P = \begin{bmatrix}{p_{11}e^{j\chi_{11}}} & {p_{12}e^{j({\partial_{12}{+ \chi_{11}}})}} & \ldots & {p_{1N}e^{j({\partial_{1N}{+ \chi_{11}}})}} \\{p_{21}e^{j\chi_{21}}} & {p_{22}e^{j({\partial_{22}{+ \chi_{21}}})}} & \ldots & {p_{2N}e^{j({\partial_{2N}{+ \chi_{21}}})}} \\ \vdots & \vdots & \ddots & \vdots \\{p_{N1}e^{j\chi_{N1}}} & {p_{N2}e^{j({\partial_{N2}{+ \chi_{N1}}})}} & \ldots & {p_{NN}e^{j({\partial_{NN}{+ \chi_{N1}}})}}\end{bmatrix}} \\{= {\begin{bmatrix}e^{j\chi_{11}} & 0 & \ldots & 0 \\0 & e^{j(\chi_{21})} & \ldots & 0 \\ \vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j(\chi_{N1})}\end{bmatrix}\begin{bmatrix}p_{11} & {p_{12}e^{j(\partial_{12})}} & \ldots & {p_{1N}e^{j(\partial_{1N})}} \\p_{21} & {p_{22}e^{j(\partial_{22})}} & \ldots & {p_{2N}e^{j(\partial_{2N})}} \\ \vdots & \vdots & \ddots & \vdots \\p_{N1} & {p_{N2}e^{j(\partial_{N2})}} & \ldots & {p_{NN}e^{j(\partial_{NN})}}\end{bmatrix}}} \\{E = {\begin{bmatrix}e^{j\chi_{11}} & 0 & \ldots & 0 \\0 & e^{j(\chi_{21})} & \ldots & 0 \\ \vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j(\chi_{N1})}\end{bmatrix}{and}}} \\{P_{B} = \begin{bmatrix}p_{11} & {p_{12}e^{j(\partial_{12})}} & \ldots & {p_{1N}e^{j(\partial_{1N})}} \\p_{21} & {p_{22}e^{j(\partial_{22})}} & \ldots & {p_{2N}e^{j(\partial_{2N})}} \\ \vdots & \vdots & \ddots & \vdots \\p_{N1} & {p_{N2}e^{j(\partial_{N2})}} & \ldots & {p_{NN}e^{j(\partial_{NN})}}\end{bmatrix}}\end{matrix}$ where N represents the number of test antennas and thenumber of receivers of the device under test, P is the propagationmatrix, p_(xy) represents a change in amplitude of a signal sent from ay^(th) test antenna to an x^(th) receiver, a value range for x and y is1 to N, e^(j(χ) ^(n1) ⁾ is phase information associated with a change inphase of the signal sent from the first test antenna to an n^(th)receiver and is unknown, ∂_(xy) is a phase difference obtained bysubtracting the change in the phase of the signal sent from the firsttest antenna to an x^(th) receiver from the change in the phase of thesignal sent from a y^(th) test antenna to the x^(th) receiver, E is amatrix of e^(j(χ) ^(n1) ⁾ obtained from the propagation matrix and isunknown, P_(B) is a matrix of p_(xy) and ∂_(xy) obtained from thepropagation matrix; and obtaining the inverse matrix based on the matrixP_(B).
 6. The tester according to claim 5, further configured to: obtainmultiple antenna patterns of multiple antennas of the device under test;and combine the multiple antenna patterns with a pre-determined MIMOpropagation channel model to obtain a MIMO propagation channel bysimulation and to generate a throughput test signal.
 7. The testeraccording to claim 5, wherein the power level reporting information isobtained by reporting, by the device under test through an antenna,power of a signal received by each receiver, or by storing locally andexporting power received.
 8. The tester of claim 5, wherein a test isperformed based on a formula: ${\begin{bmatrix}R_{1} \\R_{2} \\\vdots \\R_{N}\end{bmatrix} = {{E*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = {{\begin{bmatrix}e^{j\;\chi_{11}} & 0 & \ldots & 0 \\0 & e^{j(\;\chi_{21})} & \ldots & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j(\;\chi_{N\; 1})}\end{bmatrix}*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = \begin{bmatrix}{T_{1}*e^{j\;\chi_{11}}} \\{T_{2}*e^{j\;\chi_{21}}} \\\vdots \\{T_{N}*e^{j\;\chi_{N\; 1}}}\end{bmatrix}}}},$ where, N represents the number of antennas of thedevice under test, T represents an excitation signal at each test port,R represents a received signal at each receiver port, e^(j(χ) ^(n1) ⁾represents phase information, and E is obtained from the propagationmatrix.
 9. A non-transitory computer readable storage medium, havinginstructions stored thereon, wherein when the instructions are executedby a processor, the processor is configured to: obtain power levelreporting information of a device under test; obtain a propagationmatrix based on the power level reporting information, and obtain aninverse matrix to be loaded based on the propagation matrix to form avirtual cable between an output port of an instrument and a receiverport of the device under test; and transmit a throughput test signalthrough the virtual cable to perform a performance test on the deviceunder test and obtain a test result of radio frequency performance, theprocessor is further configured to: obtain an amplitude value based onthe power level reporting information; and obtain a phase difference ofelements in the propagation matrix based on the amplitude value toobtain the propagation matrix, the processor is further configured to:transmit a first signal through a first test antenna to each receiver ofthe device under test, obtain power level reporting information of eachreceiver, and convert the power level reporting information into a firstamplitude value of a received first signal received by each receiver,wherein the first amplitude value of the received first signalcorresponds to the first test antenna; transmit a second signal througha second test antenna to each receiver, obtain power level reportinginformation of each receiver, and convert the power level reportinginformation into a second amplitude value of a received second signalreceived by each receiver, wherein the second amplitude value of thereceived second signal corresponds to the second test antenna; repeatthe transmitting a signal, the obtaining the power level reportinginformation, and the converting the power level reporting informationuntil the amplitude value of a received signal received by each receiverand corresponding to each test antenna is obtained; transmit the firstsignal through the first test antenna and transmit the second signalthrough the second test antenna to each receiver simultaneously, obtainpower level reporting information of each receiver of the device undertest, determine an amplitude value of a synthesized signal received byeach receiver, and obtain a phase difference between a received firstsignal received by each receiver and a received second signal receivedby each receiver based on the first amplitude value, the secondamplitude value and the amplitude value of the synthesized signal; andrepeat transmitting signals by every two test antennas, obtaining thepower level reporting information, determining the amplitude value ofthe synthesized signal, and obtaining the phase difference until thephase difference between received signals received by each receiver andcorresponding to every two test antennas is obtained, so as to obtainthe propagation matrix, wherein obtaining the inverse matrix to beloaded based on the propagation matrix comprises: expressing thepropagation matrix based on a following equation: $\begin{matrix}{P = \begin{bmatrix}{p_{11}e^{j\chi_{11}}} & {p_{12}e^{j({\partial_{12}{+ \chi_{11}}})}} & \ldots & {p_{1N}e^{j({\partial_{1N}{+ \chi_{11}}})}} \\{p_{21}e^{j\chi_{21}}} & {p_{22}e^{j({\partial_{22}{+ \chi_{21}}})}} & \ldots & {p_{2N}e^{j({\partial_{2N}{+ \chi_{21}}})}} \\ \vdots & \vdots & \ddots & \vdots \\{p_{N1}e^{j\chi_{N1}}} & {p_{N2}e^{j({\partial_{N2}{+ \chi_{N1}}})}} & \ldots & {p_{NN}e^{j({\partial_{NN}{+ \chi_{N1}}})}}\end{bmatrix}} \\{= {\begin{bmatrix}e^{j\chi_{11}} & 0 & \ldots & 0 \\0 & e^{j(\chi_{21})} & \ldots & 0 \\ \vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j(\chi_{N1})}\end{bmatrix}\begin{bmatrix}p_{11} & {p_{12}e^{j(\partial_{12})}} & \ldots & {p_{1N}e^{j(\partial_{1N})}} \\p_{21} & {p_{22}e^{j(\partial_{22})}} & \ldots & {p_{2N}e^{j(\partial_{2N})}} \\ \vdots & \vdots & \ddots & \vdots \\p_{N1} & {p_{N2}e^{j(\partial_{N2})}} & \ldots & {p_{NN}e^{j(\partial_{NN})}}\end{bmatrix}}} \\{E = {\begin{bmatrix}e^{j\chi_{11}} & 0 & \ldots & 0 \\0 & e^{j(\chi_{21})} & \ldots & 0 \\ \vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j(\chi_{N1})}\end{bmatrix}{and}}} \\{P_{B} = \begin{bmatrix}p_{11} & {p_{12}e^{j(\partial_{12})}} & \ldots & {p_{1N}e^{j(\partial_{1N})}} \\p_{21} & {p_{22}e^{j(\partial_{22})}} & \ldots & {p_{2N}e^{j(\partial_{2N})}} \\ \vdots & \vdots & \ddots & \vdots \\p_{N1} & {p_{N2}e^{j(\partial_{N2})}} & \ldots & {p_{NN}e^{j(\partial_{NN})}}\end{bmatrix}}\end{matrix}$ where N represents the number of test antennas and thenumber of receivers of the device under test, P is the propagationmatrix, p_(xy) represents a change in amplitude of a signal sent from ay^(th) test antenna to an x^(th) receiver, a value range for x and y is1 to N, e^(j(χ) ^(n1) ⁾ is phase information associated with a change inphase of the signal sent from the first test antenna to an n^(th)receiver and is unknown, ∂_(xy) is a phase difference obtained bysubtracting the change in the phase of the signal sent from the firsttest antenna to an x^(th) receiver from the change in the phase of thesignal sent from a y^(th) test antenna to the x^(th) receiver, E is amatrix of e^(j(χ) ^(n1) ⁾ obtained from the propagation matrix and isunknown, P_(B) is a matrix of p_(xy) and ∂_(xy) obtained from thepropagation matrix; and obtaining the inverse matrix based on the matrixP_(B).
 10. The non-transitory computer readable storage medium of claim9, wherein the processor is further configured to: obtain multipleantenna patterns of multiple antennas of the device under test; andcombine the multiple antenna patterns with a pre-determined MIMOpropagation channel model to obtain a MIMO propagation channel bysimulation and to generate a throughput test signal.
 11. Thenon-transitory computer readable storage medium of claim 9, wherein thepower level reporting information is obtained by reporting, by thedevice under test through an antenna, power of a signal received by eachreceiver, or by storing locally and exporting power received.
 12. Thenon-transitory computer readable storage medium of claim 9, wherein atest is performed based on a formula: ${\begin{bmatrix}R_{1} \\R_{2} \\\vdots \\R_{N}\end{bmatrix} = {{E*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = {{\begin{bmatrix}e^{j\;\chi_{11}} & 0 & \ldots & 0 \\0 & e^{j(\;\chi_{21})} & \ldots & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & e^{j(\;\chi_{N\; 1})}\end{bmatrix}*\begin{bmatrix}T_{1} \\T_{2} \\\vdots \\T_{N}\end{bmatrix}} = \begin{bmatrix}{T_{1}*e^{j\;\chi_{11}}} \\{T_{2}*e^{j\;\chi_{21}}} \\\vdots \\{T_{N}*e^{j\;\chi_{N\; 1}}}\end{bmatrix}}}},$ where, N represents the number of antennas of thedevice under test, T represents an excitation signal at each test port,R represents a received signal at each receiver port, e^(j(χ) ^(n1) ⁾represents phase information, and E is obtained from the propagationmatrix.